A Practice Note examining strategies for defending lawsuits brought by private plaintiffs based on securities fraud claims. Specifically, this Note explains the scope of liability in private actions asserting material misstatements or omissions in violation of Section 10(b) and Rule 10b-5 of the Securities Exchange Act. It specifies the constraints that the Private Securities Litigation Reform Act imposes on fraud claims. It also identifies areas of overlap with other provisions of the federal securities laws, defines the elements that a plaintiff must allege and prove to prevail, and identifies the most common threshold and substantive defenses in fraud-based cases.